#include <stdio.h>
#include <stdlib.h>
const int N = 1e9;
const int M = 1048576;
double a[1024];

int main() {
    for (int i=0; i<1024; ++i) {
        a[i] = (double)(rand() % 1000) / 10;
    }
    double res = 0.0;
    for (int i=0; i<N; ++i) {
        res += a[i/M];
    }
    printf("%f\n", res);
    return 0;
}
